1. Field of the Invention
The invention relates to a control device and a control method for an engine.
2. Description of Related Art
An electromagnetic fuel injection valve that is disposed in an engine such as an automotive engine is provided with an electromagnetic solenoid and a valve body, and the valve body is opened in response to energization of the electromagnetic solenoid. The electromagnetic fuel injection valve is configured to be capable of adjusting an injection quantity by an energization time of the electromagnetic solenoid being changed. The valve body of the fuel injection valve is subjected to a bounce motion immediately after reaching a fully open position due to a reaction to a collision at a time of arrival at the fully open position. This bounce motion of the valve body results in a variation of the injection quantity of the fuel injection valve. When injection is completed before the valve body reaches the fully open position, the fuel injection is performed without being affected by the bounce motion of the valve body. In this regard, a partial lift injection technique for realizing a small-quantity injection with a high level of accuracy by performing the fuel injection with an energization time set to a length of time that is shorter than a length of time required for the valve body to reach the fully open position, which is a so-called partial lift injection, is known.
The energization time of the fuel injection valve is set based on a required injection quantity that is calculated by a base value which is set in accordance with an engine rotation speed and an engine load being corrected if necessary and the pressure of a fuel that is supplied to the fuel injection valve (fuel pressure). Japanese Patent Application Publication No. 2011-106349 (JP 2011-106349 A) discloses a technique that allows the required injection quantity to be subjected to an amount-increasing correction in accordance with a decline in the engine rotation speed at a time of an idle operation of the engine.